<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
       div{
           width: 200px;
           height: 100px;
           background-color: pink;
       }
    </style>
    <script src="jquery-1.12.2.js"></script>
    <script>
        $(function () {
            $(document).keydown(function (e) {
                var keyCode=e.keyCode;//键盘按下后的键对应的键值
                switch (keyCode){
                    case 65:$("#dv").css("backgroundColor","red");break;
                    case 66:$("#dv").css("backgroundColor","green");break;
                    case 67:$("#dv").css("backgroundColor","blue");break;
                    case 68:$("#dv").css("backgroundColor","yellow");break;
                    case 69:$("#dv").css("backgroundColor","black");break;
                }
            });
        });
    </script>
</head>
<body>
<div id="dv"></div>
</body>
</html>